1. PV204 Security technologies LABS
Introduction to smart cards
Petr Švenda
Faculty of Informatics, Masaryk University

2. The masterplan for this lab
Secure channel and smartcard communication
Building Secure Channel protocol (together)
simple protocol  design attack  fix it  iterate
Communicate with smart card (GPPro tool)
ATR, basic info, CPLC
Communicate with card programmatically
Java java.smartcardio.* or C/C++ PC/SC API
CPLC data
Obtain list of supported instructions from unknown card
| PV204: Introduction to smart cards

3. 1. Building Secure Channel protocol
Scenario: we like to transfer extrasupersensitive data between PC and smartcard
Simple protocol  design attack  fix it  iterate
Participate in discussion
(Steps and solution will be published after the labs in IS)
| PV204: Introduction to smart cards

4. 2. Communicate with smart card (GPPro)
Contact PC/SC readers + cards
GlobalPlatformPro tool
Basic smart card commands, sending APDUs
Management of GlobalPlatform cards (JavaCard)
Type gp --help for all functionality
We will use basic functionality now, rest next week
| PV204: Introduction to smart cards

5. gp --info Obtain information about smart card
Obtain ATR (Answer To Reset)
Parse using
Who is probable manufacturer of card?
What is probable OS environment for this card?
Is it JavaCard?
What is card’s circuit serial number?
When was card produced?
| PV204: Introduction to smart cards

6. gp --apdu APDU_in_hexa --debug
Send APDU command from command line
Try gp --info --debug
Can you spot APDU command to obtain CPLC info?
Send get CPLC APDU separately
gp --apdu 80CA9F7F --debug
Can you relate card’s response data and gp --info?
What is response status word?
| PV204: Introduction to smart cards

7. 3. Communicate with card programmatically
SimpleAPDU project (IS, NetBeans)
Uses Java’s javax.smartcardio.* API
CardMngr.java – utility functions for card communication
Obtain list of available readers
List readers = TerminalFactory.getDefault().terminals().list();
Connect to card
CardTerminal.isCardPresent(), CardTerminal.connect(“*”);
Obtain ATR: Card.getATR().getBytes()
Send APDU:
ResponseAPDU resp = CardChannel.transmit(apdu)
| PV204: Introduction to smart cards

8. 3. Communicate with card programmatically
Try to send get CPLC command
Pre-prepared in GetCPLCData() method
Necessary to set proper APDU
Parse response buffer
Can you relate card’s response data and gp --info?
What is value of response status word?
| PV204: Introduction to smart cards

9. Supported commands Card responds to some APDU commands
Generic ones (e.g., get CPLC data)
Custom ones (what card’s owner wants)
Usually CLA/INS/P1 only (P2 sometimes)
How to get list of commands supported by a card?
Look into documentation / standard (e.g., SIM commands)
Try to probe card (limited number of possible commands)
Be careful – many failed attempts may block your card!
| PV204: Introduction to smart cards

10. Obtain list of supported commands
Write code that will try all combination if CLA/INS
Observe response codes
Make list of CLA/INS which returns interesting code
Analyse with curiosity!
| PV204: Introduction to smart cards